I came across this series of blog entries from Etre - a usability consultancy based in London. This is an analysis of 5 different UK sites:

Dixons

Amazon

Currys

HMV

M&S

with user tracking heatmaps to measure what the website visitors are both looking at and also including what they click on. While the focus is on e-commerce sites there are very relevant lessons here for anyone who needs to increase their conversion rates.